pypa/virtualenv — pull request #178 by mcdonc (2011-10-26 14:04:33+00:00)
Title: invert site-packages behavior

Virtualenv is used, primarily, to create an isolated packaging environment. The current default use-site-packages behavior is suboptimal for this purpose. New users (and some experienced users) invariably fail to pass the flag even when instructions to do so are in blinking red text in a 72 point font, and they wind up in a place where they have conflicting global and virtualenv packages. This is, by far, the most common support issue I've experienced in regards to instructing other people to use virtualev.

It would make a lot more sense if virtualenv defaulted to ``--no-site-packages`` behavior. This patch does that, and adds a ``--use-site-packages`` flag to get the old behavior back.